Attachment for domestic boilers



March 13, 1951 F. P. ROBINSON ATTACHMENT FOR DOMESTIC BOILERS Fied oct 18, 194e 1 r f f f f f f f* Patented Mar. 13, A1951 AUNITED sTATEs PATENT OFFICE ATTACHMENT FOR DGMESTIC BOILERS Felix P. Robinson, Cottonwood, Idaho Application October 18, 1946, Serial N 0. 704,139

This invention relates to attachments lfor fireboxes and boilers for domestic heating plants, particularly such as are usually installed for heating systems of dwellings, apartments, and large buildings, and the invention is designed to increase the heating capacity of such installations through the employment of auxiliary water circulation pipes or coils, preferably installed at the side walls of the iirebox, with the ends of the coils connected to the boiler below the fire flues and to the boiler above the normal water line, so that as water is derived from the boiler and stands in the coils to the water line, the additional heating occasioned by the proximity of the coils in the rebox to the heat of the products of combustion and the expansion, due to said increased heating, causes the escape of the water at the upper end of the coil which is not obstructed by the water in the boiler, and therefore, a continuous circulation of this hot water increases the temperature of the water in the boiler and results in an economical employment of the fuel, augmenting its heating capacity, through the use of the said coils.

It is an object of this invention to provide novel means whereby the coils are connected through a wall of the rebox to the boiler and through the top wall of the rebox, the said pipe of the coil being extended so that it discharges above the water line of the boiler; and furthermore, provision is made for producing leak-proof joints between the coil and the wall of the iirebox, as well as the top plate thereof; and the said device can be readily installed in equipment now in common use and has proven inexpensive to install and maintain.

With the foregoing and other objects in view, the invention consists in the details of construction, and in the arrangement and combination of parts to be hereinafter more fully set forth and claimed. y

In describing the invention in detail, reference will be had to the accompanying drawings forming part of this application, wherein like characters denote corresponding parts in the several views, and in which: 1

Figure 1 illustrates a sectional view of a conventional type of heating boiler, showing the heating coil in elevation in the firebox; p

Figure 2 illustrates a sectional view of the equipment on the line 2 2 of Fig. 1; and

Figure 3 illustrates a sectional view of the boiler on the line 3 3 of Fig. 1.

VIn these drawings 5 denotes a conventional type of boiler having the usual re tubes 6, smoke up- 2 Claims. (Cl. 122-94) take 1, iirebox 8, ash pit 9, and furnace door It, and where coal fuel is employed, a grate Il will be used, though, in modern furnaces these may be omitted and the usual liquid or gas burners substituted.

Water circulating coils I2 and I3, each comprising a number of convolutions of pipe, are installed along each of the side walls I4 of the re box, and it is obvious that the number of convolutions may be increased or diminished, according to the size of the firebox and the diameter of the pipe employed. The lower end of each pipe projects through an aperture in the rear Wall of the rebox near the bottom of the boiler and is in communication with the boiler below the fire tubes, and it is engaged on the inner side of the wall of the firebox by a flanged nut I5 threaded on the tubes so that when the flange of the nut engages the wall of the iirebox, a tight joint is produced. The end I6 of the tube projects upwardly through the top plate of the rebox and terminates above the water line so that the water is free to discharge into the boiler and mix with the water in the boiler, and it Will assist in raising the temperature of the water of the boiler, as will be apparent. An appropriate leak-proof joint I'I of any conventional type may be employed in assembling the pipe and top plate of the boiler.

As will be understood, the boiler construction and the attachment are so arranged structurally as to be completely cooperative in developing maximum efficiency as the water-heating agency for domestic heating systems, the boiler being operatively connected with the feed and return lines leading to and from the various room heating units (not shown) contained within the heating system. For instance, the boiler is of the horizontal type with its rebox at one end and its products of combustion flue located at the opposite end and remote from the firebox, the two Zones being connected by the series of tubular ues, these extending upward toward the outlet flue at a slight angle and spaced apart sucient to permit ready circulation of water about the tubes; the major portion of the water content is located between the rebox and the outlet flue and is of considerable extent. As thus far described, the boiler is of a general type.

However, the boiler of the invention carriesY the boiler extends practically to the level of the bottom of therrebox with its top positioned a material distance above the top of the irebox,

the result being that the tubular ues are practically in the mid zone of the height of the boiler and with the depth of the water content considerably greater than that usually present in horizontal boilers-the surface level of the water content reaches into the boiler zone above the top of the rebox although such level is itself spaced from the top of the boiler. As a result, a large content volume is present, enabling a shorter boiler to 'be fused, but it tends to restrict the tubular'flue zone to an intermediate zone of the water content with resultant portions of the content depth located above and below such tubes. Since the direct heating of `this body ,is by the tubular flues, lit is essential that circulation conditions be present within such boiler portion. Generally, this condition is met by largely increasing the number of tubular iiues especially in the lower zone to provide an upward-circulation. However, with the number of tubes restricted in the present inventionand the presence of the bodies of water above and below the tube Zone, adifferent type of circulation is needed.

As indicated in the drawings, the latter is secured bythe use of the coils l2 which are ofthe ,sinuous type and located at opposite sides of the Ai'lrebox land within uthe `rebox itself, `each coil 'having its entrance at the bottom end `of the coil and extending through the rear wall of the rebox close to the bottom of the boiler, 'the coil then passing snuously in the form of con- ,nected parallel tubular portions of considerable 'length extending from `front to rear `of the fire- -box with the yportionsjmainly arranged on a vertical plane adjacent the Yside walls of the irebox and thus in close proximity to the fire within the Yfirebox, a location which serves to heatthe content-of the coil intermediate its ends with ex- -ceeding rapidity. As a result, such heated content -will rapidly rise and pass out of the upper end of the coil at its upper end and-at the same ytime cause water content from Athe bottom zone at a very highrateandthereby provide a withdrawal of water from the bottom .zone vof the boiler and thus create fa downward circulation -o the water within-theboilerat a material rate. While the latter eiect would tend to reduce'the heating effect of the fiues due tofa shorter period of contact, such resultis not present in practice,

due to the fact thatthe :highly heated -coil content is -being delivered ontothe top surface -of the boiler content in the vicinity of the intake entrance ofthe cooler water returning from-the heating system so that the top zone of the boiler content does not actually have ther-temperature of the returning water but is an admixture of the cooler returning water-and the highly heated coil content, the admixture thus raising thetern- ,perature of such top zone.

Hence, the water passing the zoneof flues 6 during theiiownward vcirculation is ,of higher temperature than `the returning water, with the result 'that' less Iheating is requiredvby the'uevzone.

From this, it can be understood that the boiler although of -comp.aratively large size and containing a large volume of water, `does not require ,e

large number of nues-twelve being yShown---and of the operationof the `device'isbelieveol unnecessary for ran understanding of the Vone skilled in the art.

invention by I claim:

1. In domestic boiler assemblages for hot water heating systems, the combination with a horizontally-extending boiler having a rebox in oneend Zone andan outlet for products of combustion in the opposite end zone, a plurality of tubular flues connecting the firebox and such opposite end zone with the flues inclined upwardly lfrom the firebox, the diameter of the boiler-being greater than the -d-epth of the rebox with the lower zone of the boiler above the lower plane of the Viirebox and the boiler'upper zone extending above the top plane of the r-ebox, such upper Zone extending in overlying relation t0 the top plane of the 'rebox with such latter plane positioned below the normal-waterlevel of the boil-er to thereby provide open communication of water content between the lmain portion ofthe boiler vand such overlying Zone below such waterlevel, the normal .water level vbeing within -suoh boiler -upper zoneand spaced ffrom the -top wall ofthe .boiler to thereby form atop space-into-which the return iiow from the heating system is delivered,

vof a pair of individual heating coils vpositioned 'within the vfrebox and adjacent the Iopposite side-walls thereof, each coil having its-lower end extending through the inner wall of the rebox and open within the lower zone of the boiler adjacent the bottomrof such zone,each oi ythe pair vof coils having its opposite end zone extending rwater content from the lower zone of the boiler to the space above the water level by the rapid temperature rise ofthe .water traversingthevcoils within therebox togincrease the rate of circulation ofthe water content of the main portion of the boiler and -tosincrease the temperature value of the returning water content from the system and therebyincrease the rapidity ,of thelcirculation.

'2. A combination -as in claim 1 characterized in that each coil has the portion-of its length that is located within the rebcxof-sinuous form with aplurality of parallel horizontally extending tubular portions each of a length approaching the front to rear length of the rebox'with corresponding ends of ,a .pair of adjacent portions connected by a curved portion and .with said p-ortions extending in .a .common vertical plane to thereby produce the sinuosity of the coil, theupper and lowerportions each includingan extensionprojecting laterally inward from such plane toward the, centralvertical zone of the lire.- box with the lower extensionthen extended laterally rearward for passage through the reboxrear `wall adjacentthebottom oithecentralzone of the boiler, the upper extension then extending ,upwardly through'the top wall ofthe iirebox into-y and through the Awater content .of theboiler zone above the rebox and above such level and then laterally rearward to thereby space the Water discharge outlet from the coil inwardly from the adjacent side wall of the boiler.

FELIX P. ROBINSON REFERENCES CITED The following references are of record in the le of this patent:

Number Re. 10,427 161,122 257,396 385,510 624,110 894,598 1,049,140 

